The present invention generally relates to rotary recording mediums and reproducing apparatuses therefor, and more particularly to a rotary recording medium capable of recording still picture information with increased recording capacity and providing fine still picture reproduction, and a reproducing apparatus for reproducing such a rotary recording medium.
Generally, a program information recorded onto a rotary recording medium (hereinafter simply referred to as a disc) is not limited to an information containing all moving pictures, but can be an information including still pictures among moving pictures. For example, in a program containing a golf lesson, titles such as "driver shot" and "bunker shot" are succeeded by the actual shots. In this case, the titles are still pictures, and the actual shots are moving pictures. When recording such a program information signal onto the disc, the still pictures are recorded on a plurality of tracks if the recording is performed under a constant speed to carry out a normal recording without discriminating the moving pictures and the still pictures. Hence, the recording range of the disc cannot be used effectively by this method, and is uneconomical. Accordingly, in order to improve the recording density, it becomes desirable to record one still picture on one track and record the moving pictures by normal recording, among the still and moving pictures.
In a reproducing apparatus for reproducing the above disc, it becomes necessary to discriminate whether the track being reproduced contains a still picture or a moving picture. With respect to a track recorded with the still picture, it is necessary to reproduce the track repeatedly for a plurality of times.
In addition, when reproducing a still picture track, there are cases where the operator wishes to skip over the still picture track by carrying out normal reproduction without carrying out still picture reproduction with respect to this still picture track in order to carry out still picture reproduction with respect to a different track. In such cases, it becomes necessary to discriminate the above different track.
Reproducing apparatuses for reproducing a disc of the electrostatic capacitance type have previously been proposed, such as the apparatuses disclosed in the U.S. Pat. Nos. 4,322,836 and 4,331,976 in which the assignee is the same as that of the present application. These previously proposed reproducing apparatuses comprise a reproducing stylus as a reproducing element for sliding and scanning over tracks on the disc to reproduce the recorded information signal as variations in the electrostatic capacitance. In such a reproducing apparatus, a track will become worn due to friction if this track is repeatedly reproduced for a long period of time due to the sliding contact between the reproducing apparatus, and this will shorten the serviceable life of the disc. Accordingly, if one still picture is recorded onto one track regardless of how long the reproducing time for this still picture is, improvements can be made with respect to the recording density, however, the serviceable life of the disc may be shortened by the still picture reproduction in the above reproducing apparatus.